1. Field of the Invention
The present invention relates generally to a dual processing system capable of ensuring real-time processing in a protocol conformance test, and, more particularly, to a dual processing system capable of ensuring real-time processing in a protocol conformance test, which processes one or more protocol test messages from a device under test in real time, and then transmits the processed messages to the device under test, thereby increasing the accuracy of a protocol test, and dealing with a communication system, the processing speed of which has been increased.
2. Description of the Related Art
FIG. 1 is a view showing the Open Systems Interconnection (OSD) 7-layer model, which is generally referred to by communication systems.
As shown in FIG. 1, the OSI 7-layer model is an international telecommunications standard protocol in which the process of communication ranging from access to termination is divided into and defined as 7 layers by the International Organization for Standardization (ISO). The lower three layers are related to data transmission over a communication network and the upper four layers are related to the processing of data transmitted over a communication network. Here, the functions of the lower three layers will be described in brief. First, a first layer, that is, a physical layer, defines the configuration, voltage, pin layout and bit transmission method of a communication cable or a connector. In particular, in the case of wireless communication, the physical layer defines a method of modulating frequencies or data. A data link layer, that is, a so-called media access control layer (hereinafter referred to as a ‘MAC’ layer), defines specifications for a data format used to accurately transmit/receive information bits, that is, data, between computers via the physical layer, and specifications used to detect errors and correct errors in the case of communication errors. Further, a network layer, that is, a so-called IP (Internet Protocol) layer, defines a function of processing data received from the data link layer.
Reference numerals 10 and 20 designate host computers for receiving and processing requests from another computer or providing specific services, and reference numerals 30 and 40 designate routers, which are devices for connecting a Local Area Network (LAN). The routers read the address of a destination from transmission information to be transmitted, designate the most appropriate communication path, and then transmit the transmission information to another communication network.
FIG. 2 is a view showing the structure of data transmitted/received between communication systems using the OSI 7 layers.
As shown in FIG. 2, data transmitted/received between communication systems is generally called a packet in association with the image of a package. Such a packet is differently called a frame, which is handled in a data link layer, a datagram, which is handled in a network layer, and a segment, which is handled in a transport layer. That is, in FIG. 2, each header is a bundle of data in which a communication protocol (hereinafter abbreviated as ‘protocol’) between peer layers is defined. When data is transmitted from a lower layer to an upper layer, the header of the lower layer is removed. In contrast, when data is transmitted from an upper layer to a lower layer, a corresponding header is attached to a received information field. For example, a frame from which a ‘PHY header’ part is removed is transmitted from the physical layer to the data link layer. Here, a protocol is a communication protocol for data to be exchanged between communication devices for data communication therebetween. That is, a protocol is rules for methods and sequences necessary to exchange data in order to accurately and desirably transmit and receive data between computers which exchange data.
Therefore, communication systems have been developed and evolved based on such protocols. In order to secure compatibility between protocol-oriented communication systems, various communication standardization organizations and service provider associations request that a certification test for protocol conformance be performed. In particular, in order to perform accurate data transmission/reception between host computers, it is of the utmost importance that a protocol conformance test between data link layers be performed.
FIG. 3 is a block diagram showing a prior art protocol conformance testing system.
As shown in FIG. 3, the structure of the prior art protocol conformance testing system includes a Device Under Test (DUT) 50, in which a layer under protocol test, for example, a data link layer, is realized; a base layer processing device 60 for processing the protocol of a layer below the layer under protocol test (hereinafter referred to as ‘base layer’), for example, a physical layer; and a protocol testing host 70 including a protocol test layer processing module 71 for transmitting a request message for a protocol test to the device under test 50 through the base layer processing device 60 and receiving a response message in response to the request message from the device under test 50, and a conformance determination module 73 for determining the conformance of the layer under protocol test realized in the device under test 50 based on the transmitted/received request and response messages. Here, the base layer processing device 60 can be realized using a communication emulator, for example, a Base Station Emulator (BSE) for supporting some of the functions of a base station in a wireless communication environment, in order to provide a communication environment identical to that of a commercialized communication system to a protocol conformance testing system.
Meanwhile, currently used methods capable of accessing the wireless Internet include a method of accessing the Internet over a mobile telecommunication network based on a platform, such as the Wireless Application Protocol (WAP) or the Wireless Internet Platform for Interoperability (WIPI), and a method of accessing the Internet over a public wireless LAN and an access point. However, the method based on the mobile telecommunication network has a fundamental limit as a general Internet access means because of the size of a screen, the limitation of an input interface, and a payment system based on a measured rate system. Further, the wireless LAN has a fundamental problem in that it has low mobility as well as a regional restriction in which the wireless LAN can be used only within a radius of several tens of meters from an access point. In order to overcome the problems, the ‘mobile Internet’ (the Worldwide Interoperability for Microwave Access (WiMAX) or Wireless Broadband (WiBro), which is the domestic standard of South Korea, as the subset of the WiMAX) has been proposed as a wireless Internet service capable of accessing the Internet at high speed while maintaining quality and cost at the same level as an Asymmetric Digital Subscriber Line (ADSL) during traveling.
As described above, with the increase in the speed of the Internet in a wireless communication environment the protocol conformance testing system has been requested to process response messages, received from the device under test in real time. However, the above-described prior art protocol conformance testing system cannot satisfy the requirement. That is, since a message transmitted/received between a device under test and the host thereof is processed through a communication emulator, the host cannot instantly deal with a message, the rapid processing of which is requested by the device under test from the host. Therefore, with regard to a slow response from the host, the device under test determines that error occurs in an access environment, and transmits an erroneous response message to the host, so that there is a problem in that error occurs in a protocol conformance test.